This invention relates to ventilation systems and more particularly to a ventilation system especially suited for use with robotic welding apparatus.
Robotic welding apparatus are in common use in industries such as the automobile industry, and typically are used in groups where each robotic welder performs a successive weld on a particular structure such, for example, as an automotive frame. Whereas robotic welders are especially efficient in performing such a serial welding operation, they generate large amounts of gaseous welding bi-products which quickly contaminate the area or enclosure in which the robotic welders are situated. The gaseous welding bi-products quickly coat everything in the area with contaminants and, more importantly, quickly make the atmosphere unsuitable for human occupation. In order to keep the atmosphere surrounding robotic welders at an acceptable purity level, it has been proposed to constantly feed large volumes of fresh air into the welding area while constantly evacuating large volume of air from the welding area so that the air in the welding area is exchanged on a frequent basis and the purity level of the air is thereby maintained at an acceptable level. However, this air-exchange methodology suffers from the disadvantage that the incoming air, especially in cold, ambient air conditions, must be heated prior to being delivered to the welding area, and the cost of heating such large quantities of air is significant and adds significantly to the overall cost of the welding operation.